This invention relates to capsule sealing and banding machines, and, more particularly, to an improved capsule support tray used as a component of these machines and a method for drying the capsules.
One manner of protecting gelatin capsules from tampering has been the placing of a gelatin band formed in situ around the juncture of a capsule cap and body after the capsule has been filled. U.S. Pat. No. 4,756,902, filed July 25, 1986, by Harvey, et. al., discloses a liquid sealing process for joining gelatin capsule segments which can also be performed on machines used conventionally for capsule banding. When performed on such a banding machine, this process involves the replacement of the fluid gelatin used for banding with a sealing fluid mixture comprising alcohol, e.g. ethanol and water, heated to a temperature of 40.degree. C. to 60.degree. C. The fluid is applied by contacting the juncture between cap and body with the solution from a reservoir conventionally filled with gelatin and positioned below the banding table by means, e.g., of a print wheel. One of the variants contemplated by the Harvey, et. al., application is the sequential application of both a sealing fluid and a banding fluid on the same machine.
In conventional banding and/or sealing machines, the capsules are fed from a supply hopper to a rotating banding table or product transfer plate via a complex set of cams, levers and push rods. This capsule feed structure has a large number of moving parts, is difficult to adjust, prone to wear and difficult to maintain in proper adjustment. Moreover, any breakdown in the feed apparatus is time-consuming and expensive to repair, and the nature of the capsule feed structure limits the number of capsule banding stations or slots which can be provided on the transfer plate. For example, one typical prior art capsule banding machine in widespread use has only six tracks or banding slots in the transfer plate.
Further, in a conventional banding or sealing machine, the capsules are conveyed by the banding table or product transfer plate to a plurality of capsule-receiving outlet transport trays which convey the capsules through a curing chamber to be cured or dried and thence to a suitable outlet or collection point. In one typical machine, these trays comprise elongate, curvilinear, trough-like devices which support the capsules on their sides. With this arrangement, the sealing material on the capsule engages the tray and may be damaged before it becomes fully dry.
Additionally, in prior art machines it is necessary to at least partially disassemble the machine in order to remove the pot or reservoir containing the sealing or banding fluid.
In other prior art machines, the capsule feed means which supplies capsules to the transfer plate incorporated rigid means to regulate the movement of capsules from the discharge end of the feed means to the transfer plate. Although it functions satisfactorily, this arrangement may result in jamming of the capsules or damage to them.